The invention relates to a suction device for fluids, especially in water needling machines in which a water beam is located outside the suction device for producing streams of fluid, possibly consisting of a suction tube with suction openings located over the working length of the tube, through which the fluid is drawn up by a vacuum produced in the tube, and sliding strips are located on both sides of and parallel to the openings along the tube to support a transport means such as a drum for the web-shaped product to be needled. The fixed suction tube must be made very stable because the vacuum to be produced is between 20 and 400 mbar. The suction tube is therefore made with a thick wall in which the suction openings are drilled. Openings made laterally along an axially parallel jacket line then form the sliding strips for the drum to be transported or a strip is provided which defines the effective suction slit by its distance.
It has been found that the width of the suction slit must be changed as a function of the transport speed of the drum or the weight of the nonwoven or the like for optimizing the suction performance, since the dewatering process is of critical importance for the needling effect. There is also the danger that the suction slit will become blocked by fiber residue, so that regular cleaning is required.
The goal of the invention is both to permit simple cleaning and also a rapid change in the width of the suction slit.
Beginning with the suction device of the type described at the outset, the solution to the problem consists in providing a replaceable cleaning strip between the sliding strips. All possible changes and sizes can be provided with this strip which can be inserted at the end, something which is not possible for the openings of the suction tube or on the permanently arranged suction strips.
The invention is not limited to water needling machines but also applies to any suction devices used in the textile industry for necessary dewatering of material.